1. Field of the Invention
The present invention relates to forming a pattern using a photoresist composition including a cyclodextrin derivative. More particularly, example embodiments of the present invention relate to a cyclodextrin derivative, a photoresist composition including the cyclodextrin derivative, and a method of forming a semiconductor device pattern using the photoresist composition.
2. Description of the Related Art
Recently, semiconductor device technology has rapidly advanced, as information media, such as personal computers, have become more widely used. Semiconductor devices are required to operate at very high speeds and to have large storage capacities. To meet recent industry trends, the manufacturing technologies of semiconductor devices have been developed to improve integration, reliability and response speeds of the semiconductor devices. In particular, a fine processing technology, such as photolithography, has enabled stricter requirements to be met, improving the degree of integration of semiconductor devices.
To fabricate a semiconductor device, a chemical amplification type photoresist composition is used in the photolithography process in order to form a photoresist pattern utilized as an etching mask. The photoresist composition is prepared by mixing a photoacid generator for generating an acid material, a polymer for sensitively reacting with the acid material, and a solvent. The photoresist composition has a variable solubility in a developing solution, which is changed in accordance with a light exposure operation. Accordingly, the photoresist pattern having a determined shape may be acquired by coating a surface of a substrate with the photoresist composition, partially exposing a photoresist film to light, and sequentially developing the exposed portions of the photoresist film.
A photoresist composition, including a polymer having a high molecular weight, has been conventionally used for forming a photoresist pattern. As a pattern in a semiconductor device becomes finer, a line width of the photoresist pattern is reduced to a molecular size of the polymer. The polymer has various molecular weights and various sizes, as well as an entangled structure. When a photoresist composition including the polymer is developed, molecules of the polymer are swollen in a developing solution, and are not dissolved in the developing solution at a constant rate. Thus, a resolution of the photoresist pattern is reduced and a line width roughness of the photoresist pattern deteriorates.
When a semiconductor device has a 240 nm dimension, a deviation of the line width roughness in a photoresist pattern is at most about 20 nm, which is about 16 percent of a line width based on both edges of the line. Thus, the deviation of the line width is inevitably generated in the method for fabricating a semiconductor device. However, as a semiconductor device having a 90 nm dimension is developed, the deviation of the line width roughness is increased to about 22 percent of the line width. When a semiconductor device has a dimension less than about 70 nm, the deviation of the line width roughness is increased to more than about 29 percent.
In order to improve the photoresist composition, a molecular weight of a polymer included in a photoresist composition has been adjusted or a type of a de-blocking group of the polymer has been changed. However, photoresist compositions having an adjusted molecular weight or a changed de-blocking group still result in great loss of a photoresist pattern in a developing process and a deterioration of mechanical properties of the polymer included in the photoresist composition. This is because a molecular size of the polymer applied to the photoresist composition is not considered.